A freshwater tank has two identical circular inspection hatches of equal area
PHYSICS · Single correct · AP · Physics 1: Algebra-based · Fluids · Fluids
Problem
A freshwater tank has two identical circular inspection hatches of equal area.
• Hatch 1 is mounted in the vertical sidewall with its center 2.0 m below the water surface.
• Hatch 2 is mounted in the horizontal bottom of the tank, also 2.0 m below the surface.
Atmospheric pressure acts on the outer faces of both hatches. Which statement correctly compares the magnitudes of the net forces exerted by the water on the two hatches?
(a) F1>F2 because the pressure on the vertical hatch increases with depth across its area, giving it a larger average pressure than the bottom hatch.
(b) F1=F2 because the centroids of both hatches are at the same depth and the areas are identical.
(c) F2>F1 because the pressure acts perpendicular to each surface, so on the bottom hatch it adds directly downward while on the side hatch it only pushes sideways.
(d) F2>F1 because in addition to the hydrostatic pressure, the weight of the water column rests directly on the bottom hatch.